Method for preparing liquid mixtures in manufacture of latex articles

ABSTRACT

A method for preparing liquid mixtures in the manufacture of latex goods in which the components entering the mixture are brought together and then mixed with the aid of ferromagnetic objects acted upon by a rotating electromagnetic field with subsequent separation of the said ferromagnetic objects from the obtained mixture by any of the known methods.

' United States Patent 1 Logvinenko et al.

[451 Nov. 27, 1973 [76] Inventors: Dmitry Danilovich Logvinenko,

ulitsa Kalinina, 5, kv. 5, Poltava; Alexei Dmitrievich Chugai, ulitsa Gvardeiskaya, 21, Kiev; Karl Lazarevich Tsantker, ulitsa Gogolya, l9, kv. 4, Poltava; Ljudmila Efirnovna Chechik, ulitsa Krasnoarmeiskaya, 58, kv. 2, Kiev; Oleg Parfirovich Shelyakov, ulitsa Kalinina, 5, kv. 100, Poltava; Mikhailovna Belonozhko, ulitsa Frunze, 108, kv. 4, Poltava; Ekaterina Alexandrovna Morozko, ulitsa K.Libknekhta, 22, Poltava; Ljudmila Nikolaevna Kuzmina, ulitsa Almaznaya, 4, kv. 191, Poltava, all of U.S.S.R.

22 Filed: Nov. 9, 1971 21 Appl. No.: 197,103

[30] Foreign Application Priority Data May 17, 1971 U.S.S.R 1652664 [5 2] US. Cl 259/1 R, 259'/DIG. 46, 259/99,

260/819 [51] Int. Cl. C08c-l/18, BOlf 13/08 [58] Field of Search 259/1 R, DIG. 46, 259/99, 100, 102, 112; 260/819, 820, 821, 822

[5 6] References Cited UNITED STATES PATENTS 2,350,534 6/1944 Rosinger 259/DIG. 46 3,219,318 11/1965 Hershler 259/1 R 2,951,689 9/1960 Asp et al.. 259/DIG. 46

Clark 259/DIG. 46

Primary ExaminerJohn Petrakes Assistant Examiner-Alan I. Cantor Att0rneyHo1man & Stern [5 7] ABSTRACT A method for preparing liquid mixtures in the manufacture of latex goods in which the components entering the mixture are brought together and then mixed with the aid of ferromagnetic objects acted upon by a 1 rotating electromagnetic field with subsequent separation of the said ferromagnetic objects from the obtained mixture by any of the known methods.

2 Claims, No Drawings METHOD FOR PREPARING LIQUID MIXTURES IN MANUFACTURE OF LATEX ARTICLES This invention relates to the methods for preparing liquid mixtures and, more particularly, to the method for preparing liquid mixtures in the manufacture of latex goods-The invention can be used in rubber industry for the manufacture of various latex articles (gloves, membranes, etc).

Methods are known in the prior art for the preparation of liquid mixtures in the manufacture of latex goods, for example, the method for preparing amixture of carbon black with a water solutionof resorcinolformaldehyde resin prepared preliminarily by the interaction between formaldehyde and multi-base phenols.

In the realization of this method, carbon black is first mixed with the aqueous solution of resorcinolformaldehyde resin in a colloid mill, after which the obtained mixture of carbon black and the resin is mixed with latex in a mixer at a pressurefrom 35 to 560 The disadvantage of this method is the impossibility of preparing liquid mixtures of carbon black with latex unless water-soluble phenol resins are added. However the addition of the phenol resins impairs theproperties of the latex articles. Furthermore, said prior art method requires additional expenditures in the preparation of soluble phenol resins by chemical methods, in building uphigh pressures and also in the complicated and insufficiently effective process equipment.

An object of the present. invention is to devise a method for preparing liquid mixtures in the manufacture of latex goods without the use of emulsifying agents which impair the properties of latex goods and with the employment of equipment of comparatively simple design and-sufticientproductive capacity.

The invention is aimed at attaining a methodfor preparing liquid mixtures in the manufacture of latex goods in which, according to the invention, the components of the mixtures are, brought together and mixed with the aid of ferromagnetic objects upon which a rotating electromagnetic field acts, with subsequent separation of the said objects from the prepared mixtures by any of the known methods.

It is recommended that the strength of the magnetic induction of the rotating electromagnetic field in the reaction mixture containing the said components should be not less than 0.08 Tesla.

In order to prevent the ingress ofcolloid metal into the latex mixture, ferromagnetic objects coated with polymers should preferably be used.

The present invention can be realized as follows: A mixture containing an aggregate, water and ferromagnetic particles, for example, steel or iron, protected with a polymer coat (for example, PVC coat) is acted upon with a running, for example, rotating electromagnetic field, having a strength of 0.08 to 0.15 Tesla. The

speed of the electromagnetic field rotation is 3,000

r.p.m.

As a result of this electromagnetic action, the ferromagnetic particles are set up in an intense motion to form the so-called vortex layer to effect the mixing and dispersing the components. At the same time, the particles oscillate electromagnetically and generate acoustic oscillations in the environing medium. Strong local,

quickly alternating magneticfields are generated imthe zone of each ferromagnetic particle.

The complex action of these factors producesactive centres on the surface of the solidparticles. Themthe mixture of the aggregate and waterisblended withithe latex mixture of rubber as was described; above.Strong bonds are formed between the. aggregateparticles. and the latex globules to improve physicalandimechanical properties of latex goods. Next, theferromagnetic particles are separated from the preparedmixture foriexample, with the aid of a magnetic separator, and the latex articles are shaped.

The proposed method has certain advantagesioxer those known in the prior art.: It can be usediforthe manufacture of latex goods with improved physical and. mechanical properties. Latex. goods; produced. on;the1 basis of liquid mixtures bythe. proposedmethod; have, a; lower cost owing to the use of cheap naturalvmaterialsiwhich can be used as the filling material without anytemulsi fying agents. The proposed. method ensures preparation of a stable mixture-of kaolin with an aqueoussolution of calcium chloride used as a fixing agentimtheimanufacture of latexesby the method of ionic deposition. The mixture does not settle out for several days, which reduces the defects in the latexproduction. The. equipment for realization of the proposed-method :is very simple from the point of view. of its designathe process for the preparation of liquid mixtures is continuousanjd can be easily. automated.

For a better understanding of the; invention by those skilled in the art,thefollowingpractical embodiments of the proposed method are given bywayofiillustration.

.Example .11

A mixture of l50gofkaolin', 350ml of waterand 180 g of steel ferromagneticparticlesll0;5 mm1long and 1.2 mm in diameter) protected with a PvC coat was placed into a1 .5 litre-capacity reaction vessel. he reaction vessel wasthen put into a zone of aquickly'rotating electromagnetic field for 11 5 1 minutes. The 1 thus prepared. mixtureof kaolin with wateriwas mixed with a latex mixture 15 parts by weight of kaolin with reference to dry weight of chloroprene rubber); ina layer. of ferromagneticparticles with simultaneous actiomofiythe rotating electromagnetic field for 10 seconds, after which theferromagnetic particles were separatedifrom the latex mixture with the. aid of a magneticseparator.

Filledlatex films were prepared :by themethodlof ionic deposition from the thuspre'paredlatex.mixture, with subsequent drying at a temperatureof Cifor one hour and curing at 120C for 2ihours.

The results of physical and mechanical testsiof'zthe thus prepared filmsshow that'the proposedwmethodq'for preparing liquidmixtures in themanufactureofilatex articles ensures the combination of alatex mixture.of chloroprene rubber with a cheap natural aggregate (kaolin) and thus strengthens considerablylatexfilms and hence improves the quality oflatexgoods (thetensile strength of non-filled latex articlesis .124.kg/sq.cm, whereas the strength of kaolin-filled latex films,pr.oduced by the proposed method is l90.kg/sq.cm,1the other indices being the same).

Example 2 A mixture of60 g of carbon black (DR- l 00), 440ml of water and g of steel ferromagnetic particles.

10.5 mm long and 1.2 mm in diameter, not protected with PVC, was placed into a reaction vessel, and placed in the zone of action of the rotating electromagnetic field for one minute. Thus prepared mixture was brought together with cloroprene rubber (10 parts by weight of carbon black with reference to the dry latex) in a layer of the ferromagnetic particles for 10 seconds, after which the ferromagnetic particles were separated from the latex mixture.

Latex films produced by the method of ionic deposition (see Example 1) were obtained from the thus prepared latex mixture. The results of physical and mechanical tests of the films show that the proposed method for preparing liquid mixtures in'the manufacture of latex articles ensures a combination of chloroprene rubber with carbon black without the use of any special emulsifying agents and ensures higher strength of latex films (the tensile strength of latex films filled with carbon black is 354 kg/sq.cm, whereas that of non-filled chloroprene films is only 124 kg/sq.cm).

Example 3 A mixture of 100 g of aerosil-175, 400 ml of water and 180 g of steel ferromagnetic particles coated with PVC (size as indicated in Example 1) was placed into a reaction vessel having the capacity indicated in Example The vessel was then put into a zone of a running electromagnetic field for minutes.

The prepared mixture was brought together with chloroprene rubber latex (20 parts by weight of aerosil with reference to dry latex weight) in the layer of the 1 same ferromagnetic particles for ten seconds.

Example 4 A mixture of components entering the composition of a fixing agent used in the manufacture of latex articles by the method of ionic deposition having the following composition 5 calcium chloride 50 g kaolin 140 g water 310 g was placed into a reaction vessel. Next 100 g of steel ferromagnetic particles of the said dimensions coated with PVC were added to the mixture and placed into the zone of a rotating electromagnetic field for ten minutes.

Latex films were prepared with the thus obtained fixing agent by the method of ionic deposition.

The results of physical and mechanical tests of the films show that the latex films prepared with the magnetic fixing agent have higher strength (some -25 20 per cent higher) compared with control films prepared with non-treated fixing agent.

Moreover, the proposed method for preparing fixing agent ensures even distribution of the positively charged calcium ions over the surface of kaolin, which in turn ensures better homegeneity of latex films (with respect to thickness). Thickness variations of films produced with non-treated fixing agent is 9 per cent, whereas those in films produced with the magnetic" fixing agent is only 3 per cent.

What is claimed is: l. A method for preparing liquid mixtures in the manufacture of latex goods which comprises:

d. separating the ferromagnetic particles from the mixture.

2. A method as of claim 1, in which the induction of the said rotating electromagnetic field is not less than 0.08 Tesla.

a. preparing a mixture of an aggregate material, 

1. A method for preparing liquid mixtures in the manufacture of latex goods which comprises: a. preparing a mixture of an aggregate material, water and ferromagnetic particles; b. placing the mixture in the zone of action of a rotating electromaGnetic field; c. blending a latex material with the mixture; and d. separating the ferromagnetic particles from the mixture.
 2. A method as of claim 1, in which the induction of the said rotating electromagnetic field is not less than 0.08 Tesla. 